Sphygmomanometer, blood pressure measurement method, and device

Abstract

A sphygmomanometer includes: a sensing cuff that includes a second sheet disposed to face the pressing member's inner circumferential surface and a first sheet facing the second sheet; a fluid storage control part providing a control of supplying and storing the pressure-transmitting fluid into sensing cuff in a worn state wherein the pressing member and sensing cuff are worn on the wrist; and a blood-pressure calculating part calculating a blood pressure based on a pressure of the pressure-transmitting fluid stored in the sensing cuff. The fluid storage control part supplies fluid in the worn state such that the first and second sheets are in contact with each other in a region corresponding to an ulna, a region corresponding to a radius, and a region corresponding to a tendon while first and second sheets are separated from each other in regions corresponding to two arteries that are radial and ulnar arteries.

The invention claimed is: 
     
       1. A sphygmomanometer comprising:
 a belt configured to be worn to wrap a wrist that is a measurement site in a circumferential direction; 
 a bag-shaped pressing cuff disposed to face an inner circumferential surface of the belt and configured to extend along the circumferential direction of the wrist to receive a supply of a fluid and compress the wrist by generating a pressing force; 
 a sensing cuff that includes a second sheet disposed to face an inner circumferential surface of the pressing cuff and a first sheet facing the second sheet, that is formed into a bag shape for storing the fluid with circumferential edge portions of the first and second sheets brought into close contact with each other, and that is configured to extend in the circumferential direction to cross an artery-passing portion of the wrist, the circumferential edge portions having two parallel long sides extending in the circumferential direction and two parallel short sides perpendicular to the two parallel long sides, the long sides and the short sides defining an entire area inside the bag shape for storing the fluid, wherein the first sheet and the second sheet are capable to separate from each other on the entire area defined by the long sides and the short sides; 
 a back plate interposed between the pressing cuff and the sensing cuff and configured to extend along the circumferential direction of the wrist to transmit the pressing force from the pressing cuff to the sensing cuff; and 
 a central processing unit that is configured to
 provide a control of compressing the wrist by the pressing cuff via the sensing cuff, 
 provide a control of supplying and storing the fluid into the sensing cuff in a worn state in which the pressing cuff and the sensing cuff are configured to be worn on the wrist, 
 calculate a blood pressure based on a pressure of the fluid stored in the sensing cuff, 
 supply the fluid in the worn state such that the first and second sheets are in contact with each other in a region corresponding to an ulna, a region corresponding to a radius, and a region corresponding to a tendon while the first and second sheets are separated from each other in regions corresponding to two arteries that are radial and ulnar arteries, and 
 provide the control of compressing the wrist by the pressing cuff via the sensing cuff in this state. 
 
 
     
     
       2. The sphygmomanometer according to  claim 1 , wherein
 the sensing cuff is provided with sags extending along a longitudinal direction of the sensing cuff in a natural state at positions leading to edge portions on both sides of the first and second sheets in a width direction of the sensing cuff. 
 
     
     
       3. The sphygmomanometer according to  claim 1 , comprising a main body equipped with a pump, wherein
 the belt extends from the main body. 
 
     
     
       4. The sphygmomanometer according to  claim 3 , wherein
 the pressing cuff, the back plate, and the sensing cuff constitute a cuff structure having a strap shape and one end attached to the main body, and wherein 
 the cuff structure further includes a curler disposed along an outer circumferential surface of the pressing cuff, wherein 
 the curler keeps a shape of the cuff structure in a natural state configured to be curved along the circumferential direction of the wrist. 
 
     
     
       5. The sphygmomanometer according to  claim 4 , wherein
 a root portion on the main body side of the curler forming the one end of the cuff structure is sandwiched between a member disposed in the main body and a back lid of the main body, so that the one end of the cuff structure is attached to the main body. 
 
     
     
       6. The sphygmomanometer according to  claim 4 , wherein
 the other end of the cuff structure on the side opposite to the one end is a free end. 
 
     
     
       7. The sphygmomanometer according to  claim 1 , wherein
 the back plate is configured to extend in a strap shape beyond the length of the sensing cuff in the circumferential direction of the wrist, and wherein 
 the back plate includes a plurality of grooves having V-shaped or U-shaped cross sections, extending in the width direction of the back plate, and being parallelly separated from each other in the longitudinal direction of the back plate, which allows the back plate to curve along the circumferential direction. 
 
     
     
       8. The sphygmomanometer according to  claim 3 , wherein
 the main body is equipped with 
 a first flow path connecting the pump and the pressing cuff to allow the fluid to flow therebetween, and 
 a second flow path connecting the pump or the first flow path and the sensing cuff to allow the fluid to flow therebetween and having an on-off valve interposed therein, wherein 
 in the worn state, the central processing unit brings the on-off valve into an opened state and supplies and stores the fluid from the pump or the first flow path through the second flow path into the sensing cuff, and wherein 
 after the fluid is stored in the sensing cuff, the central processing unit brings the on-off valve into a closed state and supplies the fluid from the pump through the first flow path to the pressing cuff to compress the wrist. 
 
     
     
       9. The sphygmomanometer according to  claim 4 , wherein
 the main body is equipped with the central processing unit. 
 
     
     
       10. A blood-pressure measurement method of measuring a blood pressure of a measurement site, by a sphygmomanometer including
 a belt configured to be worn to wrap a wrist that is the measurement site in a circumferential direction; 
 a bag-shaped pressing cuff disposed to face an inner circumferential surface of the belt and configured to extend along the circumferential direction of the wrist to receive a supply of a fluid and compress the wrist by generating a pressing force; 
 a sensing cuff that includes a second sheet disposed to face an inner circumferential surface of the pressing cuff and a first sheet facing the second sheet, that is formed into a bag shape for storing the fluid with circumferential edge portions of the first and second sheets brought into close contact with each other, and that is configured to extend in the circumferential direction to cross an artery-passing portion of the wrist, the circumferential edge portions having two parallel long sides extending in the circumferential direction and two parallel short sides perpendicular to the two parallel long sides, the long sides and the short sides defining an entire area inside the bag shape for storing the fluid, wherein the first sheet and the second sheet are capable to separate from each other on the entire area defined by the long sides and the short sides; and 
 a back plate interposed between the pressing cuff and the sensing cuff and configured to extend along the circumferential direction of the wrist to transmit the pressing force from the pressing cuff to the sensing cuff, 
 the method comprising: 
 in a worn state in which the pressing cuff and the sensing cuff are configured to be worn on the wrist, 
 supplying and storing the fluid into the sensing cuff such that the first and second sheets are in contact with each other in a region corresponding to an ulna, a region corresponding to a radius, and a region corresponding to a tendon while the first and second sheets are separated from each other in regions corresponding to two arteries that are radial and ulnar arteries; 
 providing a control in this state to compress the wrist by the pressing cuff via the sensing cuff, and 
 calculating a blood pressure based on a pressure of the fluid stored in the sensing cuff.